With Hirata-san and Washimi-san.

Summary: without actuation the F1 keystone is 18 um away from the aim (461 um) at 23.0 ºC.

Pictures at SR3 remedying work after O3.

• We removed three washers (2.007 g) from each stack of ballast masses we were working with yesterday (see album).
• With this change the F1 LVDT went to 455 um (aim is 461 um) at the temperature of the moment.
• The position of the stacks of ballast mass we modified can be seen in this diagram in the notebook.
• The initial values of the stacks of ballast masses we modified were:
  • m(+x) = 101.754 g
  • m(-x) = 37.243 g
• The final values were:
  • m(+x) = 146.918 g
  • m(-x) = 82.229 g
• The differences are
  • Dm(+x) =  45.164 g
  • Dm(-x)  =  44.986 g
  • They are only 0.178 g apart.
• In the afternoon I checked the F1 LVDT and it settled down to 443 um at 23.0 ºC, only 18 um from the aim. The keystone easily reaches 461 um with 420 counts of coil-magnet actuation.
• The current readout of the OSEMs csan be seen in this picture. and the readout before the addition of ballast mass can be found in this other picture. Comparison shows the relative position of the IRM with respect to the IM didn't not change significantly.
• The system is expected to be healthy but I will measure transfer functions tomorrow.